Multi System Disease Flashcards
What is an autoimmune disease?
A normal immune response to the wrong target in a genetically predisposed individual
Give 6 examples of organ specific aCTDs
Hashimotos Thyroiditis T1DM Anti-GBM disease Bullous phegmoid Myasthenia Gravis Pernicious anaemia
Give 9 examples of systemic aCTDs
SLE Systemic sclerosis Sjorgens syndrome Polymyositis Dermatomyositis Mixed CTD ANCA associated vasculitis IBD Psoriasis
What bedside investigations should always be done in a patient with aCTD?
RENAL function - urinalysis, BP
Obs - temp, sats
What blood tests should always be done in a patient with aCTD?
FBC, CRP, ESR, autoantibodies
Anti-La/Ro?
Sjorgens syndrome
Anti-cardiolipin?
Antiphospholipid syndrome
Anti-Jo1?
Polymyositis/dermatomyositis
pANCA for MPO?
Microscopic polyangitis
Eosinophilic polyangitis with granulomas
cANCA for RP3?
Granulomatous polyangitis
dsDNA?
SLE
Anti-RNP?
Mixed CTD
Anti-Scl70?
Diffuse systemic sclerosis
Anticentromere?
Limited systemic sclerosis
Anti-Sm?
SLE
Why is the titre important to measure?
It is the amount of times you can dilute a serum and still get the antibody - it is important as we all have some antibody in our serum
What are the DDs of aCTD?
Pain syndrome - fibromyalgia, chronic fatigue syndrome
Malignancy
Infection
Degenerative disoerder
How are ANA patterns identified?
Immunoassay or indirect fluorescent antibody
Homogenous ANA?
SLE
Speckled ANA?
SLE, MixedCTD, systemic sclerosis, sjorgens, RA
Nucleolar ANA?
Systemic sclerosis (scleroderma + crest), polymyositis
Centremere ANA?
Scleroderma, CREST
What is the pathology of SLE?
Polyclonal B cell secretion of pathogenic autoantibodies causes tissue damage via immune complex deposition and complement activation
Describe a typical history of a patient with SLE
- Young, female, afrocarribbean/asian
- Relapsing remitting
- Non specific features - malaise, weight loss, fever, sweats
- Specific features - malar/discoid rash, photosensitivity, alopecia, oral ulcer, non-erosive arthritis, raynauds, serositis, renal dysfunction, seizures, myalgia, vasculitis
What would blood tests of an SLE patient look like?
FBC - anaemia, neutropenia, thrombocytopenia, raised ESR, low complement, normal CRP
Autoantibodies - ANA, dsDNA, anti-Sm
Also might have:
HLAb8/DR2/3
EBV - precipitant
Bchrom - antihistone antibodies (drug induced)
What would biopsy show in a patient with SLE?
LE cell (macrophage that has engulfed another cell) False positive test for syphillis (VDRL)
Which drugs can cause SLE?
Minocycline, procainamide, sulphasalazine, antiepileptics, Anti-TNFa drugs
What is systemic sclerosis?
Autoimmune and vascular dysfunction, leading to fibrosis and small vessel occlusion
Describe the features of diffuse SS
Raynauds, skin thickening, digital ulcers, ILD, GI, renal cardiac complications
What autoantibodies are present in diffuse SS?
Anti-Scl70, RNA polymerase III
Describe the features of limited SS
CREST syndrome Calcinosis Raynauds Esophageal (GI involvement) Sclerodactly Telangectasia
Skin involvement limited to hands, feet and head.
Also associated with pulmonary HTN, fibrotic lung disease and mild GI disease
Which SS is related with:
a) pulmonary HTN
b) ILD
c) telangectasia
d) cardiac complications
a) limited
b) diffuse
c) limited
d) diffuse
What autoantibodies are present in limited SS
Anticentromere
What investigations should be done in a patient with SS and why?
Urine dip/BP - renal Nail fold capillaroscopy - nail changes CXR - fibrosis, ILD PFTs - restrictive in ILD HRCT - pulmonary htn Serial echo/BNP - diffuse cardiac involvement OGD - GI involvement
What are the 3 phases of Raynauds?
White - vasoconstriction
Blue - cyanosis
Red - rapid blood reflow
What causes Raynauds?
SS, SLE, MCTD, DM, PM, RA, sjorgens, vasculitis
What exacerbates Raynauds?
Cold, female, smoking, polycythemia, hypercholesterolaemia
What is the most worrying complication of diffuse SS?
RENAL CRISIS - hypertension, rapidly deteriorating function, pulmonary oedema, seizures
What a)precipitates and b)protects a renal crisis?
a) steroids
b) ACEis
What is localised scleroderma?
aka Morphea
This is scleroderma which only has skin and dermal involvement. It can has several forms:
- Linear morphea –> line of thickened skin
- Coup de sabre –> morphea on the forehead
What is Sjorgens Syndrome?
Chronic inflammatory disorder involving lymphatic infiltration and fibrosis of exocrine glands, causing ‘sicca’ symptoms. This can be primary or secondary (eg. to RA)
What are the symptoms of Sjorgens?
Dry eyes - gritty, red Dry mouth - ulcers, swelling Vaginal dryness Dry cough Dysphagia Arthralgia Fatigue
What investigations should be done in a patient with suspected Sjorgens?
Autoantibodies - Anti-Ro/La, ANA, RF
Bloods - ESR, immunoglobulins
Imaging - parotid gland biopsy
Special - Schimers tear test, salivary flow, gland biopsy
What does an anti-Ro antibody indicate and why is it dangerous?
Indicates skin involvement.
This antibody can cross the placenta to the baby and cause fetal heart block
What is the most worrying complication of Sjorgens syndrome?
Increased risk of NHL and MALT, need to monitor
What is the mechanism behind polymyositis and dermatomyositis?
Inflammatory myopathies involving striated muscle inflammation, with insidious onset.
What are the features of an inflammatory myositis?
Muscle weakness, symmetrical and affecting proximal limbs first
Insidious onset but may progress rapidly
Often spares ocular muscles
Often there are few other CTD features except ILD, but systemic features include fever, weight loss, morning stiffness
What are the characteristic cutaneous manifestations of someone with dermatomyositis?
Gottrons papules (lichenoid), flagelate, shawl sign, purple rash on eyelides with oedema, dilated capillary nail fold loops, subcutaneous calcifications
What blood tests should be done in a patient with suspected dermatomyositis/polymyositis?
Antibodies - Anti-Jo1 (PM), AntiMi2 (dermo), antisynthetase syndrome, nucleolar ANA
Bloods - CK, LDH, AST, ALT raised (muscle enzymes)
What would EMG, MRI and muscle biopsy show for a patient with PM/DM?
EMG - characteristic fibrillation potentials
MRI - oedema
Muscle biopsy - endomysial infiltrates
What investigation confirms the diagnosis of PM/DM?
Muscle biopsy - shows endomysial infiltrates